Very interesting. I have already built a high voltage low current capacitor leakage tester which has a volt meter and a micro-amp meter, however I think the neon lamp circuit would be a good idea. I may have a go at adding it to an old megger I have. Thank you for sharing.
Hi Vern ! i added your circuit to my Starkit BJ-1 which is the Japanese version of the Heathkit C-3, works like a charm. I also added a wafer switch on top of the main rotary switch to bypass the neon circuit on the 25 volts scale because i fitted the neon inside the case like the C-2 ( i used an ne-2). With this circuit i was able the sort out a cap which tested good according to the magic eye but not with the neon lamp. Thanks again, Rick
very cool! I cobbled together your circuit and put a micro amp meter in line, A good cap on electrolytic will turn the light on until it charges, then goes off as the current drops below 8 micro amps. A bad cap kept the light lit and the current high.
I used a Heathkit IT-11 tester, and tested a Mica .01uf/600v capacitor, and it tested good. I also used a parts Identifier from Amazon, that shows ESR, and that tested good (NO Res.). Then I built this tester you just showed us, and it failed at 100v. It started flashing every few seconds, and got more rapid as I left it on longer. This is a very good circuit, and I trust it more than any of the testers I have tried. Thank You very much for this simple but good tester!!!! Michael
I grew up with high voltage. It is a pleasure to see someone as casual as me around HV. However, I built MC's new ultra sensitive cap checker. I find it flawless in discovering leakage, and the count down makes it easy to validate. With my attention span the same as yours, I find it harder to watch for the blink (very dim blink). Not to say I don't like your budget box, but I am hooked once I built Carlson's and used it.
Hi Carl, there is no denying that Paul makes great test gear. I considered jumping on one also. However I have reached the point where I don't even check paper caps any more. Pull them and toss them as 99% are bad, and the rest are not far behind. Only check Molded mica and 99% of those are good. Can't justify buying something that I will hardly every use. Thanks for stopping by. By the way, show us the "guts" make a short video.
My high school electronics teacher used to toss charged (small value) caps to students. Those of us who knew him would just watch them sail by then pick them up. (He also had a shocking peanut can always on his desk.) Nowadays he'd be up on charges. Then it was just harmless teaching aid. He also taught us BIG HV caps were lethal. Had a 2uF 2000V cap he'd charge up then discharge with a copper bar hooked to a broom handle. Got EVERYONES attention. Years later that probably saved my life when a bleeder resistor opened up on a high power transformer. About 3/8" of the hot stick vaporized.... Hot sticks are a devout religion fror broadcast engineers.
Thanks for sharing this information. I built the unit and tested some caps on an old Tech TO-3 Oscilloscope. I was wondering, if I wanted to use this adapter on electrolytic caps I would need to add the switch and de 30K resistor (C3) on the Heathkit C2 schematic to adjust the sensitivity. Am I right? (I own a Heathkit IT-28 that just use the magic eye for the leakage test).
I love this idea. But is it possible to use a regular 220V E27 40W, 60W, or 100W light bulb, or is there something I should modify? Please tell me, as these are the only incandescent lamps I have access to. Thank you.
I just use my HV power supply and a microamp meter. I actually built a test setup with the meter shunted for different ranges. The setup is fairly safe, for an experienced tech. I can tell if a cap has 1ua of leakage. All caps have some leakage. There are tables available online of acceptable leakage.
Hi, I have an IT-28 set for 230V-240V. I don’t have access to those small lamps. The ones I have are only 6.3V or 12V, and I was wondering if your circuit would work with a 220V incandescent E27 standard light bulb. Or if it could be adapted for an LED.
This is a good alternative for those of us fortunate to own condenser checkers. I can see that leakage resistance in the gigaohms range is not good for mica and paper caps. What is acceptable for electrolytic caps? Do different farads as well as different voltages have different acceptable leakage? Is there a way of calculating? Or is there a printed table or chart available?
That my friend is an excellent question, and a very thorny question. Modern, low leakage, electrolytic caps often exhibit nearly zero leakage after a sufficient charge time. Older NOS caps ( perhaps 5 to 10 years old ) could be from 5uA to 5mA depending on capacitance, voltage, and a derating curve which can vary from manufacturer to manufacturer. Do a search for "allowable leakage in electrolytic capacitors" and you will find a trove of information. Capacitor testers that have an actual leakage meter ( meg ohm meter ) have charts in their manuals. Search for "Solar Capacitance Tester" or Sencore Capacitance meter, or Tel-O-Mike and you are sure to find free to download manuals with charts in them. I tend to go by ESR reading ( power factor on Heathkits and Eico units ) . Search also ESR and you will get a better understanding. Takes time and experience and searching for knowledge.
@21:58, How about adding a detector device to your unit that will take the discharge pulse and light an led brightly and for longer. This would then be much easier to read.
Hi Jonka, the idea was to keep it dead simple and cheap. Cheap being the operative word here. Pretty much describes me, Cheap and simple. And it is easier to see "in person". The camera doesn't see it very well.
The it28 doesn't have the neon lamp to indicate leakage. It uses the eye tube to indicate leakage. It will be just as sensitive, but will rely on your interpretation of how wide the spread is on the eye tube. One nice feature on the unit that you bought, is when you release the test switch it automatically discharges the capacitor. On mine if you don't remember to turn the rotary switch you can get a pretty good belt off of the cap.
I enjoyed watching this video on the comparison of both your Heathkit C-2 & C-3 condensor checkers; however though, radiotvphononut does it more eloquently in his earlier demonstrative videos on his Heathkit C-2. You could probably 'retrofit' a Heathkit C-3 with this simple circuit of your 'NE-51' tester, and presumably for the Heathkit IT-11/28 as well. Other than that, the versatile "Carlson LV Capacitor Leakage Tester" featured in the videos of Mr Carlson's Lab has what is described as 'Forecast' mode. Also, I happen to notice the black bezel rings around both the 'eye tube' and neon bulb on your C-2 (grommets?). I haven't seen such on others like it. But seriously, is it possible to use this 'NE-51' tester to check for leakage on maybe a 1 (one) farad capacitor !?!?! 73's from Houston
I opt for a capacitor tester with real operating voltage. I designed this one (see link), a bit over complicated, but it works very nice. It has a very sensitive current meter people.zeelandnet.nl/wgeeraert/radio.htm#lektest
Nice simple circuit to upgrade the classic testers. Nice to see another video from you. Hope all has been well.
Mike
Hi Mike, over worked, under paid...you know the story... Thanks for stopping by
Great to see you in action again, and a spiffy comeback that is with that neat little addon-circuit.
Cheap and simple....pretty much describes me. :-)
Very interesting. I have already built a high voltage low current capacitor leakage tester which has a volt meter and a micro-amp meter, however I think the neon lamp circuit would be a good idea. I may have a go at adding it to an old megger I have. Thank you for sharing.
Another great tip Vern, I just got a C3 from a Swapfest and plan on using the improved sensitivity circuit.
Hi Vern ! i added your circuit to my Starkit BJ-1 which is the Japanese version of the Heathkit C-3, works like a charm.
I also added a wafer switch on top of the main rotary switch to bypass the neon circuit on the 25 volts scale because i fitted the neon inside the case like the C-2 ( i used an ne-2).
With this circuit i was able the sort out a cap which tested good according to the magic eye but not with the neon lamp.
Thanks again, Rick
HI Rick, I learn something from my viewers almost every day. I had never seen the Starkit tester. And thanks for watching.
Like riding a bicycle, awesome video as always, and great to see you back on
Thanks my friend....
Thanks for the informative video. I will have to give this a try. Good to see you.
Hi Buddy, works like a charm....and cheap.
Hi RadioMechanic,
good to see you again on youtube. Keep on going
Hi Lothar, thanks. Nice to be back.
very cool! I cobbled together your circuit and put a micro amp meter in line, A good cap on electrolytic will turn the light on until it charges, then goes off as the current drops below 8 micro amps. A bad cap kept the light lit and the current high.
Good to have you back! TNX!
Hello Dino. Felt good to hop back in the saddle.
I used a Heathkit IT-11 tester, and tested a Mica .01uf/600v capacitor, and it tested good.
I also used a parts Identifier from Amazon, that shows ESR, and that tested good (NO Res.).
Then I built this tester you just showed us, and it failed at 100v. It started flashing every few seconds, and got more rapid as I left it on longer.
This is a very good circuit, and I trust it more than any of the testers I have tried.
Thank You very much for this simple but good tester!!!!
Michael
HI Michael. This is why the C-2 Heathkit is my "go to" tester. Thanks for watching.
I grew up with high voltage. It is a pleasure to see someone as casual as me around HV. However, I built MC's new ultra sensitive cap checker. I find it flawless in discovering leakage, and the count down makes it easy to validate. With my attention span the same as yours, I find it harder to watch for the blink (very dim blink). Not to say I don't like your budget box, but I am hooked once I built Carlson's and used it.
Hi Carl, there is no denying that Paul makes great test gear. I considered jumping on one also. However I have reached the point where I don't even check paper caps any more. Pull them and toss them as 99% are bad, and the rest are not far behind. Only check Molded mica and 99% of those are good. Can't justify buying something that I will hardly every use. Thanks for stopping by. By the way, show us the "guts" make a short video.
My high school electronics teacher used to toss charged (small value) caps to students. Those of us who knew him would just watch them sail by then pick them up. (He also had a shocking peanut can always on his desk.) Nowadays he'd be up on charges. Then it was just harmless teaching aid.
He also taught us BIG HV caps were lethal. Had a 2uF 2000V cap he'd charge up then discharge with a copper bar hooked to a broom handle. Got EVERYONES attention. Years later that probably saved my life when a bleeder resistor opened up on a high power transformer. About 3/8" of the hot stick vaporized.... Hot sticks are a devout religion fror broadcast engineers.
Thanks for sharing this information. I built the unit and tested some caps on an old Tech TO-3 Oscilloscope. I was wondering, if I wanted to use this adapter on electrolytic caps I would need to add the switch and de 30K resistor (C3) on the Heathkit C2 schematic to adjust the sensitivity. Am I right? (I own a Heathkit IT-28 that just use the magic eye for the leakage test).
I love this idea. But is it possible to use a regular 220V E27 40W, 60W, or 100W light bulb, or is there something I should modify?
Please tell me, as these are the only incandescent lamps I have access to.
Thank you.
I just use my HV power supply and a microamp meter. I actually built a test setup with the meter shunted for different ranges. The setup is fairly safe, for an experienced tech. I can tell if a cap has 1ua of leakage. All caps have some leakage. There are tables available online of acceptable leakage.
Hi,
I have an IT-28 set for 230V-240V. I don’t have access to those small lamps. The ones I have are only 6.3V or 12V, and I was wondering if your circuit would work with a 220V incandescent E27 standard light bulb. Or if it could be adapted for an LED.
Could you add the lamp circuit to the c3 model?
Will this circuit work with a Heathkit CT-1?
This is a good alternative for those of us fortunate to own condenser checkers. I can see that leakage resistance in the gigaohms range is not good for mica and paper caps. What is acceptable for electrolytic caps? Do different farads as well as different voltages have different acceptable leakage? Is there a way of calculating? Or is there a printed table or chart available?
That my friend is an excellent question, and a very thorny question. Modern, low leakage, electrolytic caps often exhibit nearly zero leakage after a sufficient charge time. Older NOS caps ( perhaps 5 to 10 years old ) could be from 5uA to 5mA depending on capacitance, voltage, and a derating curve which can vary from manufacturer to manufacturer. Do a search for "allowable leakage in electrolytic capacitors" and you will find a trove of information. Capacitor testers that have an actual leakage meter ( meg ohm meter ) have charts in their manuals. Search for "Solar Capacitance Tester" or Sencore Capacitance meter, or Tel-O-Mike and you are sure to find free to download manuals with charts in them. I tend to go by ESR reading ( power factor on Heathkits and Eico units ) . Search also ESR and you will get a better understanding. Takes time and experience and searching for knowledge.
Okay. Good info and thank you for pointing in a direction which will help.
Your welcome.
@21:58, How about adding a detector device to your unit that will take the discharge pulse and light an led brightly and for longer. This would then be much easier to read.
Hi Jonka, the idea was to keep it dead simple and cheap. Cheap being the operative word here. Pretty much describes me, Cheap and simple. And it is easier to see "in person". The camera doesn't see it very well.
A much more bigger problem than sensitivity, for the C3, is the false positive with ELCO with Leakage current of 250uA.
I just bought a IT-28 Is it as sensitive As your C-2 ? I have not received it yet!
The it28 doesn't have the neon lamp to indicate leakage. It uses the eye tube to indicate leakage. It will be just as sensitive, but will rely on your interpretation of how wide the spread is on the eye tube. One nice feature on the unit that you bought, is when you release the test switch it automatically discharges the capacitor. On mine if you don't remember to turn the rotary switch you can get a pretty good belt off of the cap.
Thanks for the quick reply....I'm learning a lot.
What you are doing is safer and works well though.
I like booth ways do to the fact that a lot of caps only are rated 50 or less volts
Indeed, in fact in one of my previous videos I warn against using the Heathkit on low voltage caps. Thanks for watching.
can you point out that video so I can view it
I enjoyed watching this video on the comparison of both your Heathkit C-2 & C-3 condensor checkers; however though, radiotvphononut does it more eloquently in his earlier demonstrative videos on his Heathkit C-2.
You could probably 'retrofit' a Heathkit C-3 with this simple circuit of your 'NE-51' tester, and presumably for the Heathkit IT-11/28 as well.
Other than that, the versatile "Carlson LV Capacitor Leakage Tester" featured in the videos of Mr Carlson's Lab has what is described as 'Forecast' mode.
Also, I happen to notice the black bezel rings around both the 'eye tube' and neon bulb on your C-2 (grommets?). I haven't seen such on others like it.
But seriously, is it possible to use this 'NE-51' tester to check for leakage on maybe a 1 (one) farad capacitor !?!?!
73's from Houston
It's Memorial Day 2018.
Ya, it's the drugs and old age....and the agent orange exposure from the 70's
The Radio Mechanic Me too! Getting ready for Christmas in July 😉 Big Heathkit builder and fan since I was 13!
I opt for a capacitor tester with real operating voltage. I designed this one (see link), a bit over complicated, but it works very nice.
It has a very sensitive current meter
people.zeelandnet.nl/wgeeraert/radio.htm#lektest